Refrigeration



Aug. 25, 1936. A. A. KUCHER 2,052,410

REFRIGERATION Filed Dec. 25, 1932 Patented Aug. 25, 1936 REFRIGERATION Andrew A. Kucher, Dayton, Ohio, assignor, by

mesne assignments, to General Motors Corporation, a corporation of Delaware Application December 23, 1932, Serial No. 648,694

4 Claims.

This invention relates to refrigeration.

It is among the objects of this invention to provide a refrigerating apparatus and method which are capable of providing a relatively large 5 amount of cooled drinking water with the aid of a mechanical refrigerating system of relatively small capacity.

It is also among the objects of this invention to provide a. refrigerating apparatus and method 10 in which the compressor may operate either continuously or intermittently and in which the power consumption of the refrigerating system is materially reduced automatically while the system continuesto operate notwithstanding that y lo the refrigerating capacity of the system exceeds the refrigeration demands placed upon it.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the ac- 20 companying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

The figure shows a vertical cross sectional view of an apparatus embodying features of this 5 invention.

A refrigerating apparatus embodying features of this invention and operating in accordance with my new method of refrigeration includes, in general, an object to be cooled, which in this 30 particular embodiment is a vertically disposed cylindrical water storage tank l having an uncooled water inlet II and a cooled water outlet i2. This outlet i2 leads to a combined valve and pressure reducer l3 which in turn discharges 35 into a bubbler it placed in a basin l5 at the top of the apparatus. The basin I6 is provided with a drain l6 leading to the waste lines of the building. The tank I0 is insulated as shown at H, and this insulation is covered by a metallic 40 casing I6. Preferably the tank Ill, insulation l1 and easing l8 are cylindrical and can be assembled much like the water heaters now in common operation.

A refrigerating system is placed in thermal 45 exchange with the object or water tank in such a manner that a very eflicient operation is obtained. To this end, a refrigerant translating device or motor-compressor unit 20, preferably of the type in which the motor and compressor to are sealed within a hermetic casing, delivers 55 welded along their edges and at spaced intervals within the body of the condenser in such a manner that the two sheets are slightly separated but are prevented from spreading away from each other under pressure by the spot-welds along the body thereof. Preferably the condenser 22 5 is semi-circular or semi-elliptical in'shape and is attached to the casing iii in any suitable manner so that it is spaced a sufllcient distance therefrom to permit an induced upward flow of air between the casing l8 and the condenser 22 through the flue-like space 23. The refrigerant is condensed in the condenser and is gathered in a small header 24 and discharges through the pipe 25 to an automatic expansion valve 26. The valve 26 discharges through the pipe 21 to the lower part of a vertically disposed evaporator or evaporating zone in thermal exchange relation with the object to be cooled or liquid in the tank Ill. In this particular embodiment, the evaporator is in the form of a sinuously arranged pipe forming evaporating coils 28, 29 and 30 in the tank l0. These coils are preferably separated by panels 3| and 32 to prevent the water entering at H from intermixing with the colder water in the lower portion of the tank Ill. The evaporated refrigerant discharges through the pipe 33 to a return heat interchanger 34 comprising a sinuous pipe in thermal exchange with the upper part or condensing area or zone of the condenser 22. Thereafter the evaporated refrigerant passes through the atmospheric pre-cooler 35 and returns through the pipe 36 to the motor-compressor unit 20.

The automatic expansion valve 26. is of the type which is responsive to refrigerant pressure in the 35 evaporator, automatically maintains a minimum back pressure in the evaporator. Thus the valve 26 may be so calibrated, that the refrigerant pressure in the coils 28, 29 and 30 cannot drop below the pressure corresponding to the vapor pressure 40 temperature of the refrigerant which would yield a refrigerant temperature of approximately 40 F. more or less, and if the compressor 20 should attempt to reduce the pressure below this point the valve 26 automatically opens to admit more 5 refrigerant and thus prevent the pressure from dropping below the predetermined minimum value. In view of this characteristic of the valve 26, refrigerant will be fed to the lower portion of the evaporator and will first cool the water in the compartment 40. If water is not withdrawn through the bubbler it in large quantities, the water in the compartment 40' becomes cooled to the proper temperature and then evaporation in the cell 28 practically ceases, and when more refrigerant is admitted by the valve 25 in response to the continued operation of the motor compressor unit 20, the liquid refrigerant then rises into the coil 29 where evaporation of the liquid refrigerantcools the water in thespace '4l.. Here again, if no large quantity of water is withdrawn through the bubbler I4, the evaporation of the liquid refrigerant in the coil 29 chills the water in the space 4| until the proper temperature is reached, and thereafter very little evaporation takes place in the coil 29. The liquid refrigerant then rises to the coil 30. In a like manner, evaporation in the coil 30 chills the water in the space 42 and reduces its temperature, if no larger .quantity of water is withdrawn at, until such time as the temperature in this space reaches the desired temperature. Thereafter, if the compressor 20 continues to operate, the power consumption of the refrigerating system is automatically reduced because liquid refrigerant rises from the coil 30 and overflows into theheat interchanger 34 where the excess heat absorbing power of the refrigerant is utilized by the evaporation of the liquid refrigerant to cool the condenser 22 at the condensing area or zone and thus reduce the head pressure in the condenser and reduce the load on the motor-compressor unit 20. The amount of liquid refrigerant placed in the system is such that there cannot be any liquid refrigerant overflow beyond the interchanger 34 into the pre cooler 35. The pre-cooler 35 is in the path of air rising through the space 23 and thus the evaporated refrigerant returning to the compressor 20 is cooled substantially to atmospheric temperature before admission to the compressor if the refrigerant should have become heated above atmospheric temperature in the interchanger 34.

It is within the purview of this invention that the motor-compressor unit 25 shall operate con-' tinuously without stopping for temperature ad- J'ustments, and in such cases, when the water has been cooled in the tank In and only enough refrigeration is required to maintain the water in a cooled condition, that the overflow liquid refrigerant into the interchanger 34 shall operate to.

reduce the head pressure in the condenser and hence also the power consumption because of the reduced refrigerant pressure diflerential through which the compressor must compress the refrigerant. This advantage is obtained because the interchanger 34 cools the condenser to such an extent that the pressure differential between the suction and head pressures in the refrigeration system is reduced to a minimum.

While I have described my overflow interchanger principle as applied to a water cooler in connection with a continuously operating refrigeration system, it is to be understood that this invention may be applied to objects to be cooled other than water.

Under certain conditions, it may be desirable to avoid a continuous operation of the motorcompressor unit 23, particularly where there is likely to be a long period of no demand for cooled water. Under such circumstances, a control may be provided to stop the motor-compressor unit after a suflicient amount of water has been cooled in the tank III to provide the necessary reserve capacity. To this end, a thermostatic bulb 60 may be placed in the upper part of the tank Ill, and this bulb may operate a snap switch 5| through the medium of an expansible bellows 52 and thus cause the motor to start and stop in accordance with the water temperature in the upper part of the tank l0. In this type of apparatus thev refrigeration capacity of the system while it operates may be greater than can be consumed by the thermal exchange between the evaporator and the liquid to be cooled. Under such circumstances the system tends to continue to operate with a greater power consumption than is necessary, notwithstanding the automatic control above referred to, and hence it is within the purview of this invention to utilize the advantages of my condensing area heat interchanger with an intermittently operating refrigerating system as well as with a continuously operating one.

Where the refrigerating system is designed to operate continuously, that is, without an automatic control for stopping and starting the compressor in accordance with temperatures prevailing in the apparatus, a manual control may be provided to control the starting circuits of the motor and to turn off the current when desired. To this end, the manually operable snap switch 5| closes the electric circuit 53 and starts the motor. This is accomplished by the starting relay 54 which operates to energize the common lead 55, the starting lead 56 and the running lead 25 opens the connection to and deenergizes the 30 starting lead 56 and the motor-compressor unit continues to operate by the flow of current through the leads 55and 51 in the well-known I manner. Starting relays of the character designated at 54 main common use and it is deemed 35 unnecessary further to describe them. After the motor has started, the refrigerating system continues to operate and cool the liquid in tank I! in the manner heretofore described.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Refrigerating apparatus comprising a vertically disposed tank for liquid to be cooled, means for introducing liquid into the upper part of said tank, means for withdrawing liquid from the lower part of said tank, an evaporator in thermal exchange with said liquid, a refrigerant translating device and a condenser connected to said evaporator, and means for cooling said condenser at the condensing area by refrigerant overflow from said evaporator.

2. Refrigerating apparatus comprising a tank for liquid to be cooled, means for introducing liquid into the upper part of said tank, means for withdrawing liquid from the lower part of said tank, an evaporator in thermal exchange with said liquid, 'an automatic expansion valve preventing a fall in refrigerant pressure in said evaporator I below a predetermined minimum, said valve 1 troducing refrigerant into the lower portion of said evaporator, a refrigerant translating device and a condenser connected to said evaporator, and means for cooling said condenser at the condensing area by refrigerant overflow from the upper portion of said evaporator.

3. Refrigerating apparatus comprising a vertical tank for liquid to be cooled, means for introducing liquid into the upper part of said tank, means for withdrawing liquid from the lower part of said tank, a vertically disposed evaporator in aoaaaro thermal exchange with said liquid, an automatic expansion valve responsive to refrigerant pressure within and discharging refrigerant into the lower portion of said evaporator, a condenser discharging refrigerant into said expansion valve, a refrigerant translating device discharging reirigerant into said condenser and receiving refrigerant from the upper portion of said evaporator, and an automatic control governing the operation of said translating device in accordance with the temperature of the liquid in the upper part of said tank.

4. Refrigerating apparatus comprising a vertical tank for liquid to be cooled, means for introducing liquid into the upper part of said tank, means for withdrawing liquid from the lower part of said tanlr, an upwardly directed sinuously arranged pipe forming an evaporator in thermal contact with said liquid, an automatic expansion valve responsive to refrigerant pressure within and discharging refrigerant into the lower portion of said evaporator, a condenser discharging refrigerant into said expansion valve, a refrigerant translating device discharging refrigerant into said condenser and receiving refrigerant from the upper portion of said evaporator, and an automatic control governing the operation of said translating device in accordance with the temperature of the liquid in the upper part of said tank.

ANDREW A. KUCHER. 

